Silibinin inhibits the fibrotic responses induced by cigarette smoke via suppression of TGF-β1/Smad 2/3 signaling.

Cigarette smoke (CS) is generally accepted as a major contributor to chronic obstructive pulmonary disease (COPD) which is characterized by chronic inflammation, fibrotic response, and airway obstruction. In this study, we investigated the preventive effects of silibinin, an active constitute of silymarin on CS and lipopolysaccharide (LPS) exposure-induced fibrotic response. Mice were exposed to CS for 1 h per day (8 cigarettes per day) for 4 weeks. On day 12 and 26, mice were treated with LPS intranasally. Silibinin (10 or 20 mg/kg) was administered orally 1 h before CS exposure. Silibinin markedly decreased the inflammatory cell count in the bronchoalveolar lavage fluid, and reduced levels of proinflammatory mediators. Silibinin suppressed CS + LPS-induced collagen deposition in lung tissue, as evidenced via immunohistochemistry and Masson's trichrome stain. Additionally, silibinin effectively inhibited CS + LPS-mediated expression of transforming growth factor-β1 (TGF-β1) and Smad 2/3 phosphorylation. Taken together, our data indicate that silibinin effectively inhibits the fibrotic response induced by CS + LPS exposure, possibly via suppression of TGF-β1/Smad 2/3 signaling, which results in reduced collagen deposition. These findings suggest that silibinin has therapeutic potential for the treatment of COPD.

Ko JW ，Shin NR ，Park SH ，Lee IC ，Ryu JM ，Kim HJ ，Cho YK ，Kim JC ，Shin IS ... -  《-》

Pine bark extract (Pycnogenol®) suppresses cigarette smoke-induced fibrotic response via transforming growth factor-β1/Smad family member 2/3 signaling.

Ko JW ，Shin NR ，Park SH ，Kim JS ，Cho YK ，Kim JC ，Shin IS ，Shin DH ... -  《-》

Ginsenoside Rg1 Attenuates Cigarette Smoke-Induced Pulmonary Epithelial-Mesenchymal Transition via Inhibition of the TGF-β1/Smad Pathway.

Guan S ，Xu W ，Han F ，Gu W ，Song L ，Ye W ，Liu Q ，Guo X ... -  《-》

Melatonin suppresses fibrotic responses induced by cigarette smoke via downregulation of TGF-β1.

Shin NR ，Park JW ，Lee IC ，Ko JW ，Park SH ，Kim JS ，Kim JC ，Ahn KS ，Shin IS ... -  《-》

Melatonin attenuates neutrophil inflammation and mucus secretion in cigarette smoke-induced chronic obstructive pulmonary diseases via the suppression of Erk-Sp1 signaling.

The incidence of chronic obstructive pulmonary disease (COPD) has substantially increased in recent decade. Cigarette smoke (CS) is the most important risk factor in the development of COPD. In this study, we investigated the effects of melatonin on the development of COPD using a CS and lipopolysaccharide (LPS)-induced COPD model and cigarette smoke condensate (CSC)-stimulated NCI-H292 cells, a human mucoepidermoid carcinoma cell. On day 4, the mice were treated intranasally with LPS. The mice were exposed to CS for 1 hr per day (8 cigarettes per day) from day 1 to day 7. Melatonin (10 or 20 mg/kg) was injected intraperitoneally 1 hr before CS exposure. Melatonin markedly decreased the neutrophil count in the BALF, with reduction in the proinflammatory mediators and MUC5AC. Melatonin inhibited Erk phosphorylation and Sp1 expression induced by CS and LPS treatment. Additionally, melatonin decreased airway inflammation with a reduction in myeloperoxidase expression in lung tissue. In in vitro experiments, melatonin suppressed the elevated expression of proinflammatory mediators induced by CSC treatment. Melatonin reduced Erk phosphorylation and Sp1 expression in CSC-stimulated H292 cells. In addition, cotreatment of melatonin and Erk inhibitors significantly limited the proinflammatory mediators with greater reductions in Erk phosphorylation and Sp1 expression than that observed in H292 cells treated with Erk inhibitor alone. Taken together, melatonin effectively inhibited the neutrophil airway inflammation induced by CS and LPS treatment, which was closely related to downregulation of Erk phosphorylation. These findings suggest that melatonin has a therapeutic potential for the treatment of COPD.

Shin IS ，Shin NR ，Park JW ，Jeon CM ，Hong JM ，Kwon OK ，Kim JS ，Lee IC ，Kim JC ，Oh SR ，Ahn KS ... -  《-》